Physical harm to the participants in athletic events frequently occurs as a result of collisions between themselves, such as in football, soccer, field hockey and the like. Particularly with regard to football, which involves deliberate collisions between players, school authorities have become sensitive to the risk of injury to which student participants are exposed, as well as to the liability of the school system when injury results. As a result, extensive supervised training is necessary to identify student players who engage in reckless behavior on the athletic field or who do not appreciate the dangers to which they and others are subject by certain types of impacts experienced in these athletic endeavors. One particularly troublesome problem is when a student athlete experiences a head injury, such as a concussion, of undetermined severity. In general, it is difficult to quickly determine the severity of the concussion so as to enable a coach, game official, or even a medical doctor to determine whether the student can continue play. The same problem arises in the professional sports leagues where the stakes are much higher for a team, where such a team loses a valuable player due to the possibility of a severe head injury.
Recent medical data suggest that rotational forces applied to the head and neck area (for example, flexion/extension, lateral flexion, and axial rotation) are more responsible for axonal nerve damage than previously thought. Previous medical research had indicated that axially directed forces (such as spinal compression forces) were primarily responsible for such injuries.